Synthesis and crystal structure of 2′-deoxy-2′-fluoro-4′-thioribonucleosides: substrates for the synthesis of novel modified RNAs
- 作者：Mayumi Takahashi ; Shunsuke Daidouji ; Motoo Shiro ; Noriaki Minakawa ; Akira Matsuda
- 关键词：Nucleoside ; Fluorination ; 2′ ; -Deoxy-2′ ; -fluoro-4′ ; -thionucleoside ; X-ray structure
- 刊名：Tetrahedron
- 出版年：2008
- 期刊代码：107_00404020
- 类别：ch
- 出版时间：5 May 2008
- 卷：64
- 期：19
- 页码：4313-4324
- 文件大小：478 K
摘要
We report herein the synthesis of appropriately protected 2′-deoxy-2′-fluoro-4′-thiouridine (5), -thiocytidine (7), and -thioadenosine (35) derivatives, substrates for the synthesis of novel modified RNAs. The synthesis of 5 and 7 was achieved via the reaction of 2,2′-O-anhydro-4′-thiouridine (3) with HF/pyridine in a manner similar to that of its 4′-O-congener whereas the synthesis of 35 from 4′-thioadenosine derivatives was unsuccessful. Accordingly, 35 was synthesized via the glycosylation of the fluorinated 4-thiosugar 25 with 6-chloropurine. The X-ray crystal structural analysis revealed that 2′-deoxy-2′-fluoro-4′-thiocytidine (8) adopted predominately the same C3′-endo conformation as 2′-deoxy-2′-fluorocytidine.